Please help its my actual birthday lol A beam containing a mixture of helium isotopes enters a mass spectrometer. The beam then divides into two beams that each travel to a different point on the detector. Which property do the particles in the two beams have in common? A. each particle has the same mass B. Each particle is a helium atom, not an ion C. Each particle contains the same number of neutrons D. Each particle has the same initial velocity

Each particle has the same initial velocity. This is the property which the particle have in common.

Option D

Explanation:

Mass spectrometry is the process of separating isotopes using the mass to charge ratio. As an atom is ionized to be incident on the accelerator, the atoms get converted into ions. Then based on their mass number of different isotopes with their charge, the ions will be deflected in different positions.

So, the mass to charge ratio is directly proportional to the deflection point. But the initial velocity will be same for all the ions. As the acceleration will be constant to keep the force constant. So the initial velocity will be same for all the particles.